Portal vein embolization and autologous CD133+ bone marrow stem cells for liver regeneration: initial experience

To prospectively evaluate the effectiveness of portal vein embolization (PVE) and CD133(+) bone marrow stem cell (BMSC) administration to the liver, compared with PVE alone, to augment hepatic regeneration in patients with large hepatic malignancies.

The study was approved by the institutional ethics committee; informed consent was obtained. Thirteen patients underwent PVE of liver segments I and IV-VIII to stimulate hepatic regeneration prior to extended right hepatectomy. In six patients (three men, three women; mean age, 61 years; range, 46-72 years) with a future liver remnant volume (FLRV) below 25% and/or limited quality of hepatic parenchyma, PVE alone did not promise adequate proliferation. These patients underwent BMSC administration to segments II and III (group I). In seven patients (three men, four women; mean age, 69 years; range, 63-75 years) with an FLRV below 25%, PVE alone was performed (group II). Two radiologists blinded to patients' identity and each other's results measured liver and tumor volumes with helical computed tomography. Absolute, relative, and daily FLRV gains were compared by using the t test or the Wilcoxon test.

The increase of the mean absolute FLRV in group I from 239.3 mL +/- 103.5 (standard deviation) to 417.1 mL +/- 150.4 was significantly higher than that from 286.3 mL +/- 77.1 to 395.9 mL +/- 94.1 in group II (P = .049). The relative gain of FLRV after PVE in group I (77.3% +/- 38.2) was significantly higher than that in group II (39.1% +/- 20.4) (P = .039). The daily hepatic growth rate in group I (9.5 mL/d +/- 4.3) was significantly superior to that in group II (4.1 mL/d +/- 1.9) (P = .03). Time to surgery was 27 days +/- 11 in group I and 45 days +/- 21 in group II (P = .057).

In patients with malignant liver lesions, the combination of PVE with CD133(+) BMSC administration substantially increased hepatic regeneration compared with PVE alone.